Do you have a means to independently prove that the memory chips you’re using for swaps are good?
I used one of these to prove bad 4116 and 4164 memory in my 5150 and to validate the replacement stock I bought from EBay also was working correctly.
Which kind of 5150? 16-64 or 64-256?
What other cards do you have in the 5150? Any change if you pull everything out and get down to a minimum config? (Video card, XTIDE, and MFM controller)
If you want to make your life a little easier, you can get standalone 41xx memory chip testers with ZIF sockets on EBay for quite reasonable costs.
The one I got helped me test both 4116 and 4164 chips when I was starting to fix my 5150. Found 3 bad chips in the PC, but also validated the...
Sounds like I have the same-ish Intel card.
I was able to config my Intel card in a 5150 (in a 5161) with softset2.com using the Manual mode option away from Port 300 to 260 without issue. Auto Mode didn’t work though.
I think I was still playing around with my MFM drives at that point and...
Turn off Sw2.3-2.8, otherwise the Lotech board might be in conflict with ROMs and memory regions on your video card.
Make sure you also check your motherboard DIP switches are all set correctly to 640 kB and reflect your graphic card choice.
If it helps, I ran my Sergey FDC card in a 1st gen 16-64kb 5150.
The machine was set to my minimum config
Paradise VGA
Lotech 1 Mb (640k + E000-EFFF UMB)
Sergey FDC @ C800
V20 + 3rd rev BIOS
Have you tried a Gotek FD emulator? LCD mod on that and it’s great alternative to old floppies. Couple that with a Greaseweasel to capture images from other floppy drives and you’ll have a great system.
I recently purchased one of these types of pre-assembled Sergey FDC cards off of EBay from a seller in Bulgaria.
The first card I got would work as a basic FDC with the normal 5150 Rev 3 BIOS, but the Sergey BIOS wouldn’t come up and so I couldn’t use it with my Gotek emulating a 1.44mb...
As an aside, I successfully built one of the Blasterboards mentioned on Vogons for my 5150. First time I had soldered such a large number of components in quite a number of years. It was a fun challenge and it worked! It uses physical jumpers for config, so might be an alternative for folks...
The lotech board you can get from TexElec is good. Helped me get some expansion slots back on my 5150 versus 2 * 256k cards and some additional UMB too.
Good catch! I was initially running the code off an old MFM hard drive, which seems to have started to die and is throwing bad sectors. Turns out I had data corruption problems with it and the HTTP server code too, which came along for a ride when I later transferred the code to the flash...
I vaguely remember trying out re-directing the DOS shell to the COMM port years ago, so your dream might not be totally dead.
If the source for CTTY is available, something might be sorta possible to code by those skilled in these dark arts...